[leetcode] Deepest Leaves Sum

problem

code

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public int deepestLeavesSum(TreeNode root) {
        findMaxDepth(root, 0);
        findNumsInMaxDepth(root, 0);
        return sum;
    }
    
    int sum = 0;
    public void findNumsInMaxDepth(TreeNode node, int depth) {
        if (node == null)
            return;
        
        findNumsInMaxDepth(node.left, depth + 1);
        findNumsInMaxDepth(node.right, depth + 1); 
        // System.out.println(depth + " max: " + this.max + ": " + sum);
        if (depth == max) {
            this.sum += node.val;
        }        
    }
    
    int max = 0;
    public void findMaxDepth(TreeNode node, int depth) {
        if (node == null)
            return;
        
        findMaxDepth(node.left, depth + 1);
        findMaxDepth(node.right, depth + 1);                
        this.max = Math.max(depth, this.max);

    }
}